On July 7, 2011, about 1500 Alaska daylight time, an amateur built, John D. McCarter, Sonex Waiex airplane, N18YX, received substantial damage when it collided with terrain following a loss of engine power shortly after takeoff from runway 24 at the Sterling Airpark, Sterling, Alaska. The airplane was being operated as a visual flight rules (VFR) personal flight under the provisions of 14 Code of Federal Regulations (CFR) Part 91, when the accident occurred. The sole occupant, a private pilot, sustained serious injuries. Visual meteorological conditions prevailed, and no flight plan was filed.

During a telephone conversation with the National Transportation Safety Board investigator-in-charge on July 7, an Alaska state trooper that responded to the site soon after the accident, said that witnesses reported that just after takeoff, as the airplane climbed to about 200 feet agl, all engine power was lost, followed by a rapid, nose low descent. The witnesses told the state trooper that the engine appeared to restart just before the airplane collided with the departure end of runway 24. The airplane sustained substantial damage to the wings, fuselage, and empennage.

The airplane was equipped with an 80 horsepower, 2180 cc AeroVee 2.1 engine, which is a highly modified Volkswagen engine. On July 8, 2011, two Federal Aviation Administration (FAA) airworthiness inspectors from the Anchorage Flight Standards District Office, traveled to the accident airport, and examined the airplane. The FAA inspectors reported that upon their arrival, the airplane had been moved to the pilot's home that was adjacent to the Sterling Airpark. Both inspectors reported that their examination revealed no preaccident mechanical anomalies with the engine or airframe.

Due to injuries sustained in the accident, the pilot was unable to be interviewed until after his recovery. During a telephone conversation with the NTSB IIC on November 1, 2011, the pilot reported that he has been unable to remember anything about the accident, but mentioned that the purpose of the flight was to do a local area postmaintenance test flight.